The ultimate objective of this research is to elucidate the role of the carbohydrate units on the biological activities of the glycoproteins involved in blood coagulation. Investigations during the coming year will be concerned with elucidating the carbohydrate structures of thrombin, prothrombin activation fragments and prothrombin. Each of the above wll be studied with respect to the sequence of sugar units, linkage and configuration of the glycosidic bonds, and linkage between carbohydrate and protein. The methods will include permethylation analyses, periodate oxidation and utilization of specific glycosidases on the intact glycoproteins and on isolated oligosaccharide chains. The degree of requirement of the sugar units for coagulant activity will also be investigated. Subsequent research will involve similar studies on antithrombin III, factor X and fibrinogen.